valid parentheses

 1 #include<iostream>
 2 #include<stack>
 3 #include<vector>
 4 using namespace std;
 5 
 6 class Solution {
 7 private:
 8     stack<char> sta;
 9 public:
10     bool isValid(string s) {
11         int len = s.length();
12         for (int i = 0; i < len; ++i)
13         {
14             if (s[i] == ‘(‘ || s[i] == ‘[‘ || s[i] == ‘{‘)
15                 sta.push(s[i]);
16             else
17             {
18                 if (sta.empty())//这个地方不先判空，则遇到（）] 这种情况，程序就直接崩溃了，因为对一个空栈top，你懂的
19                     return false;
20                 char temp = sta.top();
21                 sta.pop();
22                 if (temp==‘(‘&&s[i]==‘)‘||temp==‘[‘&&s[i]==‘]‘||temp==‘{‘&&s[i]==‘}‘)
23                 {
24                     ;
25                 }
26                 else return false;
27 
28             }
29         }
30         if (sta.empty())
31             return true;
32         else return false;
33     }
34 };
35 
36 int main()
37 {
38     Solution test;
39     string val = "()()]";
40     bool result = test.isValid(val);
41     cout << result << endl;
42     return 0;
43 }